The Gruyère district court in Bulle found the man, an unemployed plasterer, guilty of intentional homicide in a case that dates back to early December 2011 in the community of Neirivue.
The convicted man shot at the door of his 69-year-old landlord, who was also a neighbour living in the same building, after a dispute, the SDA news agency reported.
The shooter told the court on Tuesday he regretted the accident and he apologized to the victim’s family.
His defence lawyer argued that his client was suffering from severe back pain, was unemployed and had a drinking problem.
The court heard how the landlord, a second-hand goods dealer, had made him do odd jobs to pay for his rent, according to media reports.
When the tenant could no longer work because of his bad back, the landlord "harassed" him in a bid to make him leave the apartment.
The argument that led to the shooting erupted after the landlord and his son entered the tenant’s bedroom and seized a computer modem used to access the internet.
The tenant chased after the landlord and son who sought refuge in their apartment.
He used a rifle to fire through the four-centimetre thick door, the SDA reported.
The bullets penetrated the door and struck the victim who died from his wounds.
The victim’s 19-year-old son saw his father fall after being hit by the gun shots.
Among other charges, the accused man was convicted of weapons and drug offences.
In addition to the jail sentence, he was ordered by the court to pay 160,000 francs ($171,000) in damages to the victim’s family.
The convicted man, it turns out, was a repeat offender.
In 1995, he received a five and a half-year prison sentence for beating to death the former lover of his wife.